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Watch these 3 video clips before showing the PPT. Orca (about 2 minutes) Orca hunting sea lion pups (3 minutes)

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Presentation on theme: "Watch these 3 video clips before showing the PPT. Orca (about 2 minutes) Orca hunting sea lion pups (3 minutes)"— Presentation transcript:

1 Watch these 3 video clips before showing the PPT. Orca (about 2 minutes) Orca hunting sea lion pups (3 minutes) Orca – cooperatively hunting herring and salmon (about 3 minutes) Students should take notes during the PPT (slides 2-9) in their Orcas booklet.

2 Case study of Bioaccumulation and Biomagnification– Orcas - endangered species of Puget Sound

3 Orcas (a.k.a. killer whales)  Scientific name: Orcinus orca  Largest member of dolphin family  Identifying traits: Height of dorsal fin Saddle patch behind dorsal fin White patches on sides, belly, behind eyes

4 Orca biology  Birth weight: around 400 lbs  Adult weight – between 2.5 – 7 tons Males larger than females  Lifespan: Females: can live to over 60 years Males: live around 40 years

5 Natural History  Found in all seas, including Arctic and tropics  Travel in pods: 3 - >150 individuals  Main food: Fish Fish Squid Squid Marine mammals Marine mammals

6 Transient vs. Resident Orcas  2 major subspecies of orca  Transient orcas: Live offshore Live offshore Feed mostly on marine mammals Feed mostly on marine mammals Small pods of 3-5 individuals Small pods of 3-5 individuals Tend to be very quiet Tend to be very quiet  Resident orcas: Live near shore Live near shore Feed mostly on fish (esp. salmon) Feed mostly on fish (esp. salmon) Large pods: >20 individuals Large pods: >20 individuals Vocalize often Vocalize often

7 Puget Sound Resident Orcas  Live in extended familial units called pods  Pods are matriarchal in structure Oldest female is the grandmother of other orcas in pod Oldest female is the grandmother of other orcas in pod  Puget sound resident orcas 3 pods – J, K, L 3 pods – J, K, L Summer around San Juan islands Summer around San Juan islands Winter on Winter on the outer coast

8 Status of Southern Resident Orcas  : about 20% of southern resident orcas died – now 89 orcas  Many females of reproductive age are not producing viable young  Young males: dying rapidly Few males left in entire community  Listed as endangered species in 2005 – at risk of extinction

9 Threats to Orcas  Decreasing food supply wild salmon are also listed as an endangered species wild salmon are also listed as an endangered species  Disturbance Physical (harassment by whale watching vessels) Physical (harassment by whale watching vessels) Acoustic (low/mid frequency sonar, drilling, dredging) Acoustic (low/mid frequency sonar, drilling, dredging) Interferes with echolocationInterferes with echolocation  Environmental contamination Bioaccumulation of pollutants Bioaccumulation of pollutants  Historic threats Hunting Hunting Captured for captivity in marine parks Captured for captivity in marine parks

10 STOP HERE and have students make a food web in their booklet.

11 Please Highlight words on your worksheet you see in Yellow

12 Pollutants  Pollutant: any agent that adversely affects the health, survival, or activities of living organisms or that alters the environment in undesirable ways

13 How do pollutants enter environment?  Point source pollution – specific locations of highly concentrated pollution Factories, power plants, sewage treatment plants Factories, power plants, sewage treatment plants  Non-point source pollution –sources of pollution spread over a larger area, but less concentrated. Runoff Runoff farms, roads, golf courses, homes, etc farms, roads, golf courses, homes, etc All pollutants eventually All pollutants eventually end up in the ocean end up in the ocean

14 Types of pollutants  Water soluble pollutants Move rapidly and widely thru an environment Move rapidly and widely thru an environment  Fat soluble pollutants Inside organisms, they absorb into tissues and cells Inside organisms, they absorb into tissues and cells Stored in lipid (fat) depositsStored in lipid (fat) deposits Protected from metabolic breakdownProtected from metabolic breakdown Passed by breast milk to young in mammalsPassed by breast milk to young in mammals Tend to have much longer effects Tend to have much longer effects

15 Pollutant persistence Persistence = how long it takes to breakdown and be removed from the ecosystem  Some compounds are very unstable and degrade rapidly Concentrations decline rapidly over time Concentrations decline rapidly over time  Other compounds are specifically designed to resist degradation (don’t break-down easily) Can have severe impacts long after they are introduced Can have severe impacts long after they are introduced

16 POPs  Persistant Organic Pollutants synthetic organic compounds used in various products (from electronics to cars) that take a very long time to breakdown synthetic organic compounds used in various products (from electronics to cars) that take a very long time to breakdown Include PCBs and DDT Include PCBs and DDT  Can have very long term effects in affected ecosystems

17 PCBs: Polychlorinated biphenyls  BOTH FAT SOLUBLE AND A POP = very stable and resists degradation  Used in: transformers, pesticides, paint, small electric parts, etc from  Enter mainly through non-point sources: products with PCBs leak, PCB travels into soil, carried by wind and water into environment (and eventually the ocean)  In rats – cause liver cancer, pituitary tumors, leukemia, lymphoma and intestinal cancer  In humans, classified as a probable human carcinogen (cancer causer) → banned in 1977

18 Bioaccumulation  Process by which cells absorb and store a great variety of molecules Allows cell to accumulate nutrients and essential minerals (like calcium, phosphorus, etc.) Allows cell to accumulate nutrients and essential minerals (like calcium, phosphorus, etc.) However, same process can also absorb and store harmful pollutants inside an organism However, same process can also absorb and store harmful pollutants inside an organism Reason some fish are not fit for human consumption (usually because of bioaccumulation of mercury)Reason some fish are not fit for human consumption (usually because of bioaccumulation of mercury)

19 Biomagnification  Process by which the effects of pollutants are magnified up an ecosystem through food chains When organism consumed by a higher trophic level, only about 10% of energy moves up, however majority of the pollutant is passed on from prey to consumer When organism consumed by a higher trophic level, only about 10% of energy moves up, however majority of the pollutant is passed on from prey to consumer Therefore – as the pollutant moves up the food chain, the concentration of the pollutant in the body tissue increases dramatically Therefore – as the pollutant moves up the food chain, the concentration of the pollutant in the body tissue increases dramatically This is especially true for POPs since they persist for long periods of time This is especially true for POPs since they persist for long periods of time

20 Biomagnification Example DDT residues - Long Island Estuary Woodwell, Wurster, Isaacson, 1967 Trophic level Organism DDT (wet weight) PrimaryProducer Green alga 0.08 ppm (parts per million) PrimaryConsumer Mud snail 0.26 ppm SecondaryConsumer Summer Flounder 1.28 ppm TertiaryConsumer Ring-billed gull 75.5 ppm

21 Puget sound orcas affected by PCB’s  Our orcas have, on average, the highest measured levels of PCB’s of any marine mammal IN THE WORLD  Almost 150 ppm (parts per million) average >10 ppm PCB known to cause immune problems in seals >10 ppm PCB known to cause immune problems in seals Mother can pass as much as 90% of PCB’s to her offspring via milk and through placenta Mother can pass as much as 90% of PCB’s to her offspring via milk and through placenta Female transient orca found dead on Dungeness spit in 2002 had 1000 ppm Female transient orca found dead on Dungeness spit in 2002 had 1000 ppm

22 Yeah, but they are are banned, right?  Double whammy for our orcas PCB’s are less harmful when in fat vs. their bloodstream PCB’s are less harmful when in fat vs. their bloodstream Low salmon runs = orcas use blubber (fat) for energy Low salmon runs = orcas use blubber (fat) for energy↓ PCB’s released into blood ↓ PCBs interfere with normal immune function ↓ Result: orcas more susceptible to disease and pathogens

23 Yeah, but PCB’s are banned, right? - other POP’s – the ‘Dirty Dozen’ POP (persistent organic pollutant) Pesticide Industrial Chemical By-product Aldrin√ Chlordane√ DDT√ Dieldrin√ Endrin√ Heptachlor√ Mirex√ Toxaphene√ Hexachlorobenzene√√√ PCBs√√ Dioxins√ Furans√

24 New era, new threats  Many countries still use chemicals that have proven to bioaccumulate  Chemicals are stored all over the world and are often not properly disposed of  US does not have a law that insists on testing of new chemicals (unless they are used in food) Only 10% of the 85,000 chemicals used in North America have been tested for environmental effects Only 10% of the 85,000 chemicals used in North America have been tested for environmental effects

25 PBDEs: example of a new threat  Polybrominated diphenyl ethers  Group of fire-retardant chemicals (they don’t catch fire)  A POP: structurally similar to PCB’s  Found in furniture, televisions, computers  Europe has banned PBDE’s, only state to ban is California  There IS an available fire retardant shown not to bioaccumulate

26  The First orca calf since 2012 was born to the southern residents in September Their population had just dipped to

27 Now complete the Analysis Questions on pages 5-8 in your Orcas booklet. Use complete sentences.

28 Extra credit  Research report on: PBDE’s or another currently used pollutant PBDE’s or another currently used pollutant Use at least 3 different sources (and provide bibliography) Use at least 3 different sources (and provide bibliography) Include: Include: Chemical structureChemical structure What it is used in/ for (pros)What it is used in/ for (pros) Environmental/ health impacts (cons)Environmental/ health impacts (cons) Statement on whether you believe it should continue to be used or outlawedStatement on whether you believe it should continue to be used or outlawed Now complete the Analysis Questions on pages 5-8 in your Orcas booklet. Use complete sentences.


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